JP2703086B2 - Internal observation device for combustible liquefied gas storage tank - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention relates to the inside of a combustible liquefied gas storage tank for observing the inside of a combustible liquefied gas storage tank for storing LNG, LN ₂ , LPG, etc. in combination with a lighting device. The present invention relates to an observation device.

(Prior art) For flammable liquefied gas storage tanks such as LNG and LPG, monitor whether the storage tank interior equipment (valves, measuring equipment, etc.) and the storage tank wall are maintained in good condition. In addition, it is necessary to observe the behavior of the liquid level when the tank oscillates.

FIGS. 12 and 13 show a conventional example of an internal observation device for observing the inside of the combustible liquefied gas storage tank. Among them, the internal monitoring device shown in FIG. 12 has a comparatively long observation cylinder (c) suspended downward from the upper wall (b) of the combustible liquefied gas storage tank (a). A transparent glass part (d) for observation is provided at an appropriate position on the lower side surface of (c), and an illumination lamp (e), an observation prism (f), and an observation endoscope ( g) to observe the storage tank wall including the upper wall (b) of the combustible liquefied gas storage tank (a).

In the internal observation device shown in FIG. 13, an observation cylinder (c) is vertically installed downward from the upper wall (b) of the combustible liquefied gas storage tank (a), and the observation cylinder (c) is provided. The lower end is opened in the upper part of the storage tank (a), and a partitioning means (h) is provided at the upper and lower middle part of the observation cylinder (c) so as to be retractable outside the observation cylinder (c). A storage section (p) of an observation device main body (i) described later is formed in the observation cylinder (c) above the partitioning means (h).

The side wall of the storage unit (p) is used for exchanging the imaging means (q) and the illumination means (r) of the body (l) of the observation device body (i) suspended on the storage part (p). An opening door (t) is provided.

The observation device body (i) includes an upper base (j) and a support (k) attached to a lower portion of the upper base (j) so as to be pivotable about a vertical axis, and a lower end of the support (k). And a container (l) attached to the portion so as to be able to undulate around a horizontal axis (m).

This container (l) is provided with an imaging means (q) and an illumination means (r). When the container (l) is projected downward from the lower end opening of the observation cylinder (c), the upper base (j) is inserted into the lower end opening of the observation cylinder (c). Observation cylinder (c) supporting means (s) for supporting
It is provided inside.

(U) is a conduit through which a wire supplying electric power to each of the driving means passes, and the conduit (u) is the observation device main body (i).
And projecting outside through the inside of the observation cylinder (c).

Then, the partitioning means (h) is retracted to the outside of the observation cylinder (c), and then the wire rope of the wire lifting mechanism (n) is drawn out, and the observation device main body (i) in the storage portion (p) is flammable liquefied. After lowering into the gas storage tank (a) and supporting the observation device main body (i) by the support means (s), the driving means moves the body (l) of the observation device main body (i) around the vertical axis. Or monitor the inside of the combustible liquefied gas storage tank (a) by using the imaging means (q) and the illuminating means of this vessel (l) in combination with the horizontal axis (m). In addition, the behavior of the liquid surface such as sloshing in the combustible liquefied gas storage tank (a) is observed.

(Problems to be Solved by the Invention) Since the flammable liquefied gas storage tank (a) shown in FIGS. 12 and 13 stores therein a flammable liquefied gas such as LNG and LPG, an internal observation device is used. When observing the inside of the combustible liquefied gas storage tank (a), it is necessary to provide explosion-proof means in the internal observation device to ensure the safety of the combustible liquefied gas storage tank (a).

The present invention has been made in view of the above problems, and has as its object the purpose of the present invention to observe the safety of a flammable liquefied gas storage tank when observing the inside of the flammable liquefied gas storage tank for storing flammable liquefied gas such as LNG and LPG. Another object of the present invention is to provide a device for observing the inside of a combustible liquefied gas storage tank, which can ensure the performance.

(Means for Solving the Problems) In order to achieve the above object, the apparatus for observing the inside of a combustible liquefied gas storage tank of the present invention is provided above a combustible liquefied gas storage tank fed out from a winding drum device. A flexible hose for suspension hanging down through the opening into the storage tank, and a rotating device casing attached to a lower end of the flexible hose for suspension so as to be capable of rotating about the axis of the flexible hose for suspension. A heat insulation box for a camera mounted on the lower end of the swing device casing so as to be able to undulate around a horizontal axis, an observation camera mounted in the heat insulation box for the camera, the rotation device casing and the camera A flexible hose for communication between the interior of the heat insulation box, the flexible hose for suspension from the winding drum device, the casing for the swivel device, and the flexible cable for communication. A cable extending through the internal space of the hose to the inside of the thermal insulation box for the camera, and connecting the inert gas supplied to the winding drum device with the flexible hose for suspension and the casing of the rotating device. An inert gas is filled inside the camera system by introducing it into the camera insulation box via the inside of the flexible hose for the camera.

(Operation) The apparatus for observing the inside of a combustible liquefied gas storage tank according to the present invention is configured as described above. (I) When observing the inside of the combustible liquefied gas storage tank, the inert gas fed to the winding drum device is used. It is introduced into the interior of the camera insulation box via the interior of the suspension flexible hose, the swivel casing, and the communication flexible hose, and is filled with an inert gas to protect the explosion. In addition, after rotating the camera insulation box in the falling direction around the horizontal axis so that the center axis of the camera insulation box coincides with the center axis of the swivel casing (the swivel casing and the camera insulation box are connected in series). Then, the take-up drum device is driven, the suspension flexible hose is drawn out, and the opening provided in the upper part of the combustible liquefied gas storage tank (if the storage tank is an existing storage tank, the existing base is used). It is suspended inside the combustible liquefied gas storage tank through a nozzle with a valve (safety valve nozzle), and is stably held by a suspension flexible hose at a predetermined height so as not to twist (sway). At this time, the swivel casing is swiveled around the axis of the hose as necessary, and the camera insulation box is rotated upright about the horizontal axis, so that the camera insulation box is tilted horizontally and vertically. Is adjusted, and the condition inside the combustible liquefied gas storage tank is observed with the observation camera in the thermal insulation box for the camera. (Ii) After observing the inside of the flammable liquefied gas storage tank, the camera insulation box is rotated by its own weight in the falling direction around the horizontal axis, and the center axis of the camera insulation box coincides with the center axis of the swivel casing. (The swivel casing and the thermal insulation box for the camera are arranged in series in the vertical direction.) Is closed to keep the inside of the combustible liquefied gas storage tank closed.

(Embodiment) Next, an apparatus for observing the inside of a combustible liquefied gas storage tank of the present invention will be described with reference to an embodiment shown in FIGS. 1 to 3.

(1) is an inner tank portion of a combustible liquefied gas storage tank, (2) is an outer tank portion of a combustible liquefied gas storage tank, and (3) is an inner and outer tank portion (1).
(4) is a combustible liquefied gas in the combustible liquefied gas storage tank, (5) is an opening provided on the upper part of the combustible liquefied gas storage tank, and (6) is an opening provided in the combustible liquefied gas storage tank. ) Is the main valve provided on the upper opening side.

Since the opening (5) uses an internal observation device to be described later, its inner diameter is significantly smaller than that of the conventional observation cylinder (c) shown in FIGS. In the case of a liquefied gas storage tank, the existing nozzle with a main valve is used as it is.

Next, the winding drum device will be described. As shown in FIG. 4, the drum winding device includes a winding drum (18), a drum casing (20), a hollow winding drum shaft (37), a joint (38), a guide pulley (39), and the same guide pulley. (39) Guide shaft (40), rotation transmission mechanism (41), seal ring (42), gear (43), winding drum drive motor (44), seal ring (45), ring casing (46) It is composed of a slip ring (47), an external cable (48), and a pipe (49).

This winding drum device is disposed above a combustible liquefied gas storage tank, and one end of a suspension flexible hose (16) is connected to a winding drum (18) of the winding drum device via a joint (38). The other end of the flexible hose for suspension (16) is fixed and the flammable liquefied gas storage tank (1) (2)
It hangs down inside the combustible liquefied gas storage tanks (1), (2) and (3) through an opening (5) provided in the upper part of (3).

As the suspension flexible hose (16), for example, a stainless steel hose that is stable in strength even at a low temperature is used. Although this stainless steel flexible hose has folds, it basically has a high torsional rigidity due to its closed cross section, and stably holds the camera insulation box (7) in the observation direction. I do.

In addition, the upper cover (15) of the swivel casing (10) is attached to the lower end of the suspension flexible hose (16), and the swivel casing (10) swings around the hollow rotating shaft (30) of the upper cover (15). Mounted as possible.

Inside the turning device casing (10), a low-temperature drive motor (32) of a turning drive mechanism (14) is fixed, and a speed reducer (31) is connected to the low-temperature drive motor (32) and the hollow rotary motor. It is interposed between the shaft (30).

Below the turning drive mechanism (14), a low-temperature drive motor (33) of the undulation drive mechanism (11) is fixed in the turning device casing (10). A take-up pulley (35) and a direction change pulley (36) are rotatably mounted on the outer end of the swivel casing (10), respectively. (35) and the low-temperature drive motor (33) are connected.

As shown in FIG. 3, the camera insulation box (7) is mounted so as to be able to undulate around a horizontal axis provided at the lowermost end of the swivel casing (10).

This camera insulation box (7) is composed of a heat insulation box rear part (25) having the horizontal axis at the rear part and a heat insulation box front part (23) equipped with an observation camera described later. The insulated box front (23) holds the insulated box rear (25) in a watertight state.

The camera insulation box (7) uses the following heat insulating material, ie, mylar (aluminum deposited on synthetic resin) as a shield, and a thin spacer (glass fiber or the like) interposed between adjacent shields. The camera insulation box (7) may be made by using a heat insulating material in which a vacuum is applied between the Mylar layers while the outer surface is covered with the heat insulating material.

One end of an up-and-down drive wire (12) from a winding pulley (35) provided at a lower end of a casing (10) of the turning device is fixed to the camera heat insulation box (7).

In addition, a TV camera (8) as an observation camera and an electric zoom lens (9) are installed inside the camera heat insulation box (7).
And a pressure sensor (24) for measuring the degree of vacuum in the heat insulating material, a sensor and heaters (27) are attached.

An outer glass (21) and an inner glass (22) are attached to the front opening of the camera insulation box (7), and a space therebetween communicates with the heat insulating material of the insulation box front part (23). I have.

A communication flexible hose (13) is attached between the turning device casing (10) and the rear part (25) of the thermal insulation box (7) for the camera, and the insides thereof communicate with each other.

Cables (17) are cables (wires that share and support the suspended load, power cables, and cables composed of tubes for sending inert gas, etc.). After passing through the inside of the lower flexible hose (16) and the upper cover (15), it enters the swivel casing (10), where it is wound around the hollow shaft (30) several times. It extends to the inside of the camera warm box (7) through the inside of (13).

The power cable is used to drive the drive motors (32) and (33) in the swivel casing (10), the observation camera (8) in the camera warm box (7), and the electric zoom lens (9). (Not shown). The opposite end (winding drum side end) of the cables (17) is attached to a slip ring (47) through the inside of a hollow winding drum shaft (37), and the slip ring (47) is Connected to external cable (48). Further, the inside of the heat insulating material of the camera heat insulating box (7) is evacuated from a vacuum exhaust port (28) provided in the front part (23) of the heat insulating box.

The suspension flexible hose (16) is wound on a winding drum (18) via a direction changing pulley (19).
If there is a space above the opening (5), the take-up drum (18) may be arranged at the position of the direction changing pulley (19). In place of the observation camera (8), a steel camera, a lightwave side ranger, or the like may be incorporated in place of the observation camera (8).

Next, the operation of the apparatus for observing the inside of the combustible liquefied gas storage tank shown in FIGS. 1 to 3 will be specifically described.

Activate the low-temperature drive motor (33), transmit its rotation to the take-up pulley (35), rotate the take-up pulley (35) in the pay-out direction, and pay out the undulating drive wire (12). After rotating the heat insulation box (7) in the falling direction about the horizontal axis so that the center axis of the camera heat insulation box (7) coincides with the center axis of the rotating device casing (10), the motor for driving the winding drum is driven. (44) is started, and its rotation is transmitted to the hollow winding drum shaft (37) and the winding drum (18) via the gear (43), and the hollow winding drum shaft (37) and the winding drum are rotated. (18)
Is rotated in the unreeling direction, and the flexible hose for suspension (1
6) is pulled out, and the swivel casing (10) and the thermal insulation box (7) for the camera are suspended through the opening (5) into the combustible liquefied gas storage tanks (1), (2) and (3).

In this case, the suspension flexible hose (16) having a high torsional rigidity is stably held at a predetermined height position so as not to cause torsion (run-out). In addition, the low-temperature drive motor (32) is started, the rotation is transmitted to the swing device casing (10), and the swing device casing (10) is turned around the hollow rotary shaft (30). (33) is started, the rotation is transmitted to the winding pulley (35), the winding pulley (35) is rotated in the winding direction, the undulating drive wire (12) is wound, and the camera warm box ( 7) is rotated in the upright direction about the horizontal rotation axis to adjust the horizontal and vertical inclination angles of the camera warm box (7).

Next, the state inside the low-temperature liquefied gas storage tanks (1), (2), and (3) is observed by the observation camera (8) and the electric zoom lens (9) in the camera warm box (7), and is obtained at this time. The video signal is sent to a monitor television (not shown) via cables (17) → slip ring (47) → external cable (48) to be visualized.

At that time, an illumination lamp (not shown) is inserted into the storage tank through an insertion port provided separately on the upper wall of the storage tank to illuminate the storage tank brightly, and inert gas is supplied to the winding drum (18) of the winding drum device. ), Through the interior of the flexible hose for suspension (16), the interior of the swivel casing (10) and the interior of the flexible hose for communication (13), and into the interior of the thermal insulation box (7) for the camera. Fill the inside with inert gas to prevent explosion.

Also, at this time, the degree of vacuum inside the heat insulator of the camera insulation box (7) is detected by the pressure sensor (24), and if the pressure drop of the inert gas is detected, or if the gas is stored in the combustible liquefied gas storage tank ( 1) If the sensor (27) of the camera warm box (7) is detected to have entered the camera warm box (7) from inside (2) (3), the oxygen concentration of the surrounding gas is further reduced. If it is detected that oxygen is contained in the surrounding gas, double explosion protection is performed by means such as cutting off the power supply through cables (17) to ensure safety.

When the power supply is cut off, the electromagnetic clutch of the speed reducer (34) is turned off, and the low-temperature drive motor (33) and the winding pulley (35) are idled by the weight of the camera warm box (7), and the undulation drive wire (12) is turned off. ) To keep the camera warm box (7)
Is rotated in the falling direction about the horizontal axis so that the center axis of the camera warm box (7) coincides with the center axis of the swivel casing (10), and the swivel casing (10) and the camera warm box ( 7) is taken out from the opening (5).

In addition, even when a strong force is applied to the undulation drive wire (12) and the undulation drive wire (12) is broken, the turning device casing (10) and the camera insulation box (7) are placed in series vertically. Then, the swivel casing (10) and the camera insulation box (7) are taken out from the opening (5).

FIG. 5 shows that the turning device casing (10) is composed of an outer casing (52a) and an inner casing (52b).
A vacuum laminated heat insulator (52c) is provided between them, and the speed reducer (53) and the room temperature drive motor (54) of the swing drive mechanism and the room temperature drive motor on the undulation drive mechanism side are provided in the swing device casing (10). (56) and a speed reducer with an electromagnetic clutch (57). A pulley (58) is attached to the rear of the camera warm box (7). The other end of the undulating drive wire (12) extending through (36) is wound around the pulley (58), and the wire breaking mechanism (5
0) is provided in this embodiment.
The same operation as the embodiment shown in FIGS. 3 to 3 is performed.

In this embodiment, the following operation is performed. That is, when the turning device casing (10) and the camera insulation box (7) are pulled up in the combustible liquefied gas storage tank in the state shown in FIG. 5, the camera insulation box (7) is hooked on the opening (5). Thus, the swivel casing (10) and the thermal insulation box (7) for the camera cannot be taken out of the flammable liquefied gas storage tank. At this time, in this embodiment, the undulating drive wire (12) is tensioned, and the wire breaking mechanism is used. The bolt (65) (see Fig. 6) provided on the (50) is broken, and the swivel casing (10) and the thermal insulation box (7) for the camera are connected in series. It can be taken out of the gas storage tank.

In FIG. 6, the bolt (65) is screwed into the pulley (58), the end fitting (66) of the wire (12) is attached to the bolt (65), and the bolt (65) is fixed to a predetermined wire tension. Breaks due to

Fig. 7 shows a bevel gear (7
1), the bevel gear (71) is attached to the output shaft of the reduction gear with electromagnetic clutch (34) (67), the drive shaft (68),
This is an embodiment in which the camera holding box (7) is driven up and down by a bevel gear (70).

In this embodiment, the same operation as the embodiment shown in FIGS. 1 to 3 is performed. That is, as shown in FIG. 8, the notched key (73) provided between the bevel gear (71) and the undulating rotating shaft (72) is broken by a predetermined force, and the rotating shaft (72)
Even if the camera insulation box (7) fixed to the unit is caught in the opening, the swivel casing (10) and the camera insulation box (7) are connected in series, and the combustible liquefied gas storage tank is opened through the opening. It can be taken out.

FIG. 9 shows a state in which a rotary encoder (60) is attached to one end of a hollow winding drum shaft (37) that penetrates through the drum casing (20) and protrudes into the casing (46). Another embodiment in which one end of the cables (17) in the inside is connected to an external cable (48) via a curl cable (59). In this embodiment, the embodiment shown in FIGS. The same operation as described above is performed.

Figs. 10 and 11 consist of multiple thin-walled pipes (61) made of stainless steel, aluminum alloy, FRP, etc., and stoppers (63) (64) fixed to the upper and lower ends of each thin-walled pipe (61). Still another embodiment in which the telescopic telescopic tube surrounds the flexible hose for suspension (16), while the upper end of the telescopic telescopic tube is attached to the casing of the direction change pulley (19) via the fixing bracket (62). In this embodiment, the same operation as in the embodiment shown in FIGS. 1 to 3 is performed. Further, since the suspension flexible hose (16) is surrounded by the telescopic telescopic tubes (61) to (64), the flexible hose for suspension (16) is prevented from being deteriorated or damaged at an early stage.

(Effects of the Invention) The present invention provides a suspension flexible hose and a swiveling device casing for supplying inert gas supplied to a winding drum device when observing the inside of a combustible liquefied gas storage tank with an internal observation device as described above. To the interior of the thermal insulation box for the camera via the inside of the flexible hose for communication with the device, and to fill the inside of these devices with inert gas to perform explosion proof.
The safety of the flammable liquefied gas storage tank can be ensured when observing the inside of the flammable liquefied gas storage tank storing the flammable liquefied gas.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view showing an embodiment of an internal observation device for a combustible liquefied gas storage tank according to the present invention, FIG. 2 is a longitudinal sectional side view of a thermal insulation box for a camera, and FIG. FIG. 4 is a longitudinal side view of the winding drum device, FIG. 5 is a longitudinal side view showing another embodiment of the internal observation device, and FIG. 6 is a broken bolt of the embodiment. , FIG. 7 is a longitudinal sectional side view showing another embodiment of the internal observation device, FIG. 8 is a cross-sectional plan view showing a broken notched key of the embodiment, and FIG. FIG. 10 is a longitudinal sectional view showing another embodiment of the connecting drum shaft part, FIG. 10 is a longitudinal sectional side view showing another embodiment of the connecting flexible hose part, and FIG. FIGS. 12, 13 are longitudinal sectional side views showing respective examples of a conventional apparatus for observing the inside of a combustible liquefied gas storage tank. (1) (2) (3) ... flammable liquefied gas storage tank, (4) ...
Combustible liquefied gas, (5) Opening, (7) Insulating box for camera, (8) Observation camera, (9) Electric zoom lens, (10) Swivel casing ,(13)
... Flexible hose for communication, (16) ... Flexible hose for suspension, (17) ... Cables, (18), (20)
(37) to (49) ... winding drum device, (23) ... front part of the heat insulation box, (25) ... rear part of the heat insulation box.

 ──────────────────────────────────────────────────続 き Continued on front page (72) Inventor Yoshihiko Kubota 1-3-1, Uchisaiwaicho, Chiyoda-ku, Tokyo Tokyo Electric Power Company (72) Inventor Nobuyuki Nishioka 12-nishikicho, Naka-ku, Yokohama-shi, Kanagawa Mitsubishi Heavy Industries, Ltd. (72) Inventor Tomokichi Inabe 2-1-1 Shinhama, Arai-machi, Takasago City, Hyogo Prefecture Inside the Takasago Research Laboratory, Mitsubishi Heavy Industries, Ltd. (56) References JP-A-49-97515 (JP, A) JP-A Sho 63-133047 (JP, A)

Claims (1)

(57) [Claims] 1. A hanging flexible hose which is fed from a winding drum device and hangs down through an opening provided in an upper portion of a combustible liquefied gas storage tank into the storage tank, and a lower end of the hanging flexible hose. A swivel casing mounted so as to be pivotable about the axis of the suspension flexible hose, and a camera insulation box mounted at the lower end of the swivel casing so as to be able to undulate about a horizontal axis. A camera for observation mounted in the heat insulation box for the camera, a flexible hose for communication between the revolving device casing and the heat insulation box for the camera, and a flexible hose for suspension from the winding drum device. A cable extending through the internal space between the swivel casing and the communication flexible hose to the inside of the camera insulation box; The inert gas supplied to the ram device is introduced into the camera heat insulation box via the suspension flexible hose, the swivel device casing, and the communication flexible hose, and is introduced into the interior of these equipment systems. A device for observing the inside of a combustible liquefied gas storage tank, characterized in that the inside is filled with an inert gas.